1 /*
2 * OSS compatible sequencer driver
3 *
4 * seq_oss_readq.c - MIDI input queue
5 *
6 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #include "seq_oss_readq.h"
24 #include "seq_oss_event.h"
25 #include <sound/seq_oss_legacy.h>
26 #include "../seq_lock.h"
27 #include <linux/wait.h>
28
29 /*
30 * constants
31 */
32 //#define SNDRV_SEQ_OSS_MAX_TIMEOUT (unsigned long)(-1)
33 #define SNDRV_SEQ_OSS_MAX_TIMEOUT (HZ * 3600)
34
35
36 /*
37 * prototypes
38 */
39
40
41 /*
42 * create a read queue
43 */
44 struct seq_oss_readq *
45 snd_seq_oss_readq_new(struct seq_oss_devinfo *dp, int maxlen)
46 {
47 struct seq_oss_readq *q;
48
49 if ((q = kzalloc(sizeof(*q), GFP_KERNEL)) == NULL) {
50 snd_printk(KERN_ERR "can't malloc read queue\n");
51 return NULL;
52 }
53
54 if ((q->q = kcalloc(maxlen, sizeof(union evrec), GFP_KERNEL)) == NULL) {
55 snd_printk(KERN_ERR "can't malloc read queue buffer\n");
56 kfree(q);
57 return NULL;
58 }
59
60 q->maxlen = maxlen;
61 q->qlen = 0;
62 q->head = q->tail = 0;
63 init_waitqueue_head(&q->midi_sleep);
64 spin_lock_init(&q->lock);
65 q->pre_event_timeout = SNDRV_SEQ_OSS_MAX_TIMEOUT;
66 q->input_time = (unsigned long)-1;
67
68 return q;
69 }
70
71 /*
72 * delete the read queue
73 */
74 void
75 snd_seq_oss_readq_delete(struct seq_oss_readq *q)
76 {
77 if (q) {
78 kfree(q->q);
79 kfree(q);
80 }
81 }
82
83 /*
84 * reset the read queue
85 */
86 void
87 snd_seq_oss_readq_clear(struct seq_oss_readq *q)
88 {
89 if (q->qlen) {
90 q->qlen = 0;
91 q->head = q->tail = 0;
92 }
93 /* if someone sleeping, wake'em up */
94 if (waitqueue_active(&q->midi_sleep))
95 wake_up(&q->midi_sleep);
96 q->input_time = (unsigned long)-1;
97 }
98
99 /*
100 * put a midi byte
101 */
102 int
103 snd_seq_oss_readq_puts(struct seq_oss_readq *q, int dev, unsigned char *data, int len)
104 {
105 union evrec rec;
106 int result;
107
108 memset(&rec, 0, sizeof(rec));
109 rec.c[0] = SEQ_MIDIPUTC;
110 rec.c[2] = dev;
111
112 while (len-- > 0) {
113 rec.c[1] = *data++;
114 result = snd_seq_oss_readq_put_event(q, &rec);
115 if (result < 0)
116 return result;
117 }
118 return 0;
119 }
120
121 /*
122 * copy an event to input queue:
123 * return zero if enqueued
124 */
125 int
126 snd_seq_oss_readq_put_event(struct seq_oss_readq *q, union evrec *ev)
127 {
128 unsigned long flags;
129
130 spin_lock_irqsave(&q->lock, flags);
131 if (q->qlen >= q->maxlen - 1) {
132 spin_unlock_irqrestore(&q->lock, flags);
133 return -ENOMEM;
134 }
135
136 memcpy(&q->q[q->tail], ev, sizeof(*ev));
137 q->tail = (q->tail + 1) % q->maxlen;
138 q->qlen++;
139
140 /* wake up sleeper */
141 if (waitqueue_active(&q->midi_sleep))
142 wake_up(&q->midi_sleep);
143
144 spin_unlock_irqrestore(&q->lock, flags);
145
146 return 0;
147 }
148
149
150 /*
151 * pop queue
152 * caller must hold lock
153 */
154 int
155 snd_seq_oss_readq_pick(struct seq_oss_readq *q, union evrec *rec)
156 {
157 if (q->qlen == 0)
158 return -EAGAIN;
159 memcpy(rec, &q->q[q->head], sizeof(*rec));
160 return 0;
161 }
162
163 /*
164 * sleep until ready
165 */
166 void
167 snd_seq_oss_readq_wait(struct seq_oss_readq *q)
168 {
169 wait_event_interruptible_timeout(q->midi_sleep,
170 (q->qlen > 0 || q->head == q->tail),
171 q->pre_event_timeout);
172 }
173
174 /*
175 * drain one record
176 * caller must hold lock
177 */
178 void
179 snd_seq_oss_readq_free(struct seq_oss_readq *q)
180 {
181 if (q->qlen > 0) {
182 q->head = (q->head + 1) % q->maxlen;
183 q->qlen--;
184 }
185 }
186
187 /*
188 * polling/select:
189 * return non-zero if readq is not empty.
190 */
191 unsigned int
192 snd_seq_oss_readq_poll(struct seq_oss_readq *q, struct file *file, poll_table *wait)
193 {
194 poll_wait(file, &q->midi_sleep, wait);
195 return q->qlen;
196 }
197
198 /*
199 * put a timestamp
200 */
201 int
202 snd_seq_oss_readq_put_timestamp(struct seq_oss_readq *q, unsigned long curt, int seq_mode)
203 {
204 if (curt != q->input_time) {
205 union evrec rec;
206 memset(&rec, 0, sizeof(rec));
207 switch (seq_mode) {
208 case SNDRV_SEQ_OSS_MODE_SYNTH:
209 rec.echo = (curt << 8) | SEQ_WAIT;
210 snd_seq_oss_readq_put_event(q, &rec);
211 break;
212 case SNDRV_SEQ_OSS_MODE_MUSIC:
213 rec.t.code = EV_TIMING;
214 rec.t.cmd = TMR_WAIT_ABS;
215 rec.t.time = curt;
216 snd_seq_oss_readq_put_event(q, &rec);
217 break;
218 }
219 q->input_time = curt;
220 }
221 return 0;
222 }
223
224
225 #ifdef CONFIG_PROC_FS
226 /*
227 * proc interface
228 */
229 void
230 snd_seq_oss_readq_info_read(struct seq_oss_readq *q, struct snd_info_buffer *buf)
231 {
232 snd_iprintf(buf, " read queue [%s] length = %d : tick = %ld\n",
233 (waitqueue_active(&q->midi_sleep) ? "sleeping":"running"),
234 q->qlen, q->input_time);
235 }
236 #endif /* CONFIG_PROC_FS */
237
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